1. Field of the Invention
The present invention relates to a cleaning device for a vehicular lamp and more particularly to a cleaning device for cleaning the font cover of a vehicular lamp.
2. Description of the Related Art
A cleaning device for a vehicular lamp is mounted in a vehicle such as an automobile and cleans dirt off the front cover (front cover lens) of a headlamp.
The cleaning device for a vehicular lamp substantially has a spray nozzle on the distal end of a piston that is driven in and out of (or retracted into and extended from) a cylinder. When a cleaning fluid (water) is supplied to the inside of the cylinder, the piston projects out of the cylinder by the fluid pressure and allows the cleaning fluid to be sprayed out from the spray nozzle toward the front cover of the vehicular lamp. When the supply of the cleaning fluid is stopped, the piston returns to the inside of the cylinder by a spring installed between the cylinder and the piston.
In this cleaning device, the spray nozzle at the distal end of the piston is moved out and then moved back into the vehicle body through the opening (hole) formed in, for instance, a bumper. When the spray nozzle is retracted from the opening into the vehicle body, the opening is not necessary, and leaving the opening uncovered worsens the overall appearance. Moreover, there is a risk of damage or the like. Airborne objects such as pebbles kicked up by a rear wheel of a vehicle in front would hit the spray nozzle or the like.
In the cleaning device for a vehicular lamp disclosed in Japanese Patent Application Laid-Open (Kokai) No. 2002-347584, the opening for the spray nozzle is covered by a nozzle cover that is mounted on the distal end of the piston when the spray nozzle is retracted from the opening into the vehicle body. This structure provides an improved overall appearance and eliminates the risk of airborne objects such as pebbles hitting the spray nozzle or the like via the opening.
In the above-described cleaning device, the nozzle cover is fixed to the piston by two screws. Accordingly, the problem is that additional effort is required for assembling the nozzle cover. Furthermore, the nozzle cover is attached to the piston with the distal end of the piston retracted from the opening into the vehicle body. Thus, the work space for such attachment is extremely small, and it is not easy to tighten the screws in such a small space.
Japanese Patent Application Laid-Open (Kokai) No. 8-58532 discloses another cleaning device for a vehicular lamp in which the nozzle cover is attached to the distal end of the piston via a ball and socket joint mechanism. In this cleaning device, the nozzle cover is attached to the distal end of the piston by simply pushing a part of the nozzle cover (that forms a part of the ball and socket joint) from the outside to the inside of the opening of a vehicle body and then joining a part of the nozzle cover to a part of the ball and socket joint that is provided on the distal end of the piston.
However, in this cleaning device of Japanese Patent Application Laid-Open (Kokai) No. 8-58532, the nozzle cover and the distal end of the piston are joined at only one point of the ball and socket joint mechanism, and such joining is made merely by fitting a ball and a socket. Accordingly, the problem is that when an external force is applied to the nozzle cover, the nozzle cover can easily be dislodged from the vehicle body.